The present invention relates to rain screen siding systems including siding boards that may be of wood and devices for supporting the siding boards spaced apart from but parallel with plywood or other sheathing of a building wall structure.
Wooden siding, even when painted, is porous enough to absorb moisture from humid air, rain, or other precipitation, and to be dried by long exposure to dry hot air and direct sunlight, during different weather conditions or times of the year.
Particularly in wet climates, siding boards fastened closely to a wall structure such as plywood sheathing covered with a waterproof or water-resistant weather barrier membrane may be continuously damp on and adjacent their inner faces, even while the outer surfaces of the siding boards may become dry enough in hot, dry, weather to begin to shrink and cause the boards to cup. Over time, this may result in siding boards beginning to crack or rot or harbor ants or other insect pests.
In well-known rain screen siding arrangements furring strips are fastened on the outside of weather barrier membranes over plywood sheathing or other structural members on the outside of a building wall framework. Siding boards are fastened to the furring strips and are thus spaced outwardly apart from the weather barrier membranes, so that air can circulate between the siding boards and the weather barrier membrane, to help the inner faces of siding boards to shed moisture and thus avoid deterioration for a longer time. An air space between the siding boards and the underlayment membranes provides some thermal insulation in both hot and cold weather conditions. Siding boards, however, must be nailed or screwed directly to the furring strips.
Clips for supporting siding boards in a rain screen arrangement are known as shown in Hikai U.S. Pat. No. 6,598,362. The clips disclosed by Hikai are designed to support parallel siding boards that have overlapping edge portions, with the siding boards spaced apart from an underlying building wall surface such as an underlayment weather barrier membrane on a plywood sheathing, but with the edges of adjacent siding boards closely adjacent to one another, thus forming a substantially tight layer of siding boards albeit separated from the supporting building wall framework and its sheathing and underlayment membrane by an air space.
Guffey U.S. Pat. No. D617,011 discloses a design for a rain screen system in which a supporting clip extends around an upper edge of a lower siding board and into a groove in a lower edge of an upper siding board, supporting the adjacent upper and lower siding boards with a space defined between their edges. Guffey fails, however, to explain how the clips are to be attached to a building wall structure.
Hotta U.S. Patent Application Publication Document No. US 2002/0046536 A1 discloses another siding support member to support siding boards with overlapping, tightly adjacent edges, but with an air space between the assembled siding boards and an exterior surface of a supporting building wall framework and its underlayments.
What is needed, then, is a system for supporting a rain screen siding arrangement that is not limited to the previously known horizontal orientation of each siding board, and that provides a ventilated air space between siding boards and a supporting wall framework, sheathing, and underlayment membranes.